Crankpin grinding apparatus



Feb. 1, 1949. A. G. BELDEN ETAL 2,460,731

CRNKPIN GRINDING APPARATUS Filed May 21, 1947 v 5 sheets-sheet 1 /NVENTOE,

' TTORNEY 111111949. ,1 G, BELDEN ETAL 2,460,731

CRANKP IN GRINDING APPAATUS Filed May 21, 1947 3 Sheets-Sheet 2 /N VENraz p?. a @Laser G. Bewan Cnel. GY FLyqneE.

A. G. BEI-DEN ET AL CRANKPIN GRINDING APPARATUS Feb. 1, 1949.

3 Sheets-Sheet 3 Filed May 21, 1947 NVENTOR I 4 Lasfer Gf BELDEH Cnel.FLvqmeE Bvwwumaxm QrrolaNEv Patented Feb. 1, 1949 CRANKPIN VGrRINDINGrAPPARATUS Albert G. Belden and Carl G. Flygare, Worcester, Mass.,assignors to Norton Company, Worcester, Mass., a corporation ofMassachusetts Application May 21, 1947, .Serial No. 749,414

6 Claims.

The invention relates to grinding machines, and

more particularly to a crankpin grinding machine. One object of theinvention is to provide a simple and thoroughly practical crankpingrinding machine. Another object is to provide a crankpin grindingattachment for a standard cylindrical grinding machine. Anotherobjeot ofthe invention is to provide a crankshaft supporting chuck adapted foruse on cylindrical grinding machine. Another object is to provide acrankshaft supporting chuck which is arranged to be drivingly supportedon the hea'dstock of a cylindrical grinding machine. A further object isto provide a crankshaft supporting chuck, one end of which is yieldablysupported on the headstock.

and the other end of which is supported by a steadyrest. Other objectswill be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts, as will beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claims.

One embodiment of the invention has been illustrated in the accompanyingdrawings, in

which like reference numerals'indicate like parts and wherein: l

Fig. 1 is a front View of a cylindrical grinding machine embodying theinvention;

Fig. 2 is a vertical sectional view, on an enlarged scale, through thecrankshaft supporting chuck, showing the chuck drivingly and yieldablesupported on the headstock center;

Fig. Sis a right hand end elevation of the chuck; and

Fig. 4 is an end elevation of the crankshaft supporting chuck, showingthe steadyrest support for the end portion of the chuck.

Ar cylindrical grinding machine is illustrated in the drawingscomprising a base HJ which serves as va lsupport for a longitudinallyreciprocable work table II. The table II supports a headstock I2. A`rotatable grinding wheel I5 is mounted on the left hand end of a wheelspindle i6. :The spindle is rotatably journalled in bearings (not shown)in a transversely movable wheel slide il. A grinding wheel drivingmechanism is provided comprising an electric motor i8 mounted on theupper surface of the wheel slide I6. The motor I8 is provided with adriving pulley is which is connected by means of a belt 20 with a pulley2l on the right hand end of the spindle I6.

The grinding wheel l5 and slide Il may be fedtransyersely relative -tothe base I0 by means. of

with a gear 3l.

a feeding mechanism including a manually operable feed wheel 22. Thefeed wheel 22 is connected to rotate a gear 23 which is mounted en theforward end of a fed screw shaft 24. The shaft 24 serves to rotate afeed screw (not shown) which meshes with a half nut (not shown) de`pending from the underside of the wheel slide II. It will be readilyapparent from the foregoing disclosure that a manualrotation of the feedwheel 22 will impart a transverse movement to the wheel slide I'I andthe grinding wheel I5. The grinding wheel I 5 may be fed automaticallyby means of a pawl 25 which is `arranged to engage teeth on theperiphery of the feed wheel 22. A hydraulically operated actuating motorcontained in the case 26 which is controlled by a table reversing lever21 is provided to actuate thepawl 25 automatically during reversal ofthe table II at the ends of its reciprocatory stroke.

This mechanism has not been shown in detail since it is not consideredto be a part of the present invention. This mechanism is substantiallyidentical to that shown in the prior United States Patent No. 2,071,677to W. H. Wood dated February 23, 1937 to which reference may be had fordetails of disclosure not contained herein.

Almanually operable table traverse mechanism is provided to facilitatepositioning the table relative to the grinding wheel I5. This mechanismmay comprise a manually operable traverse `wheel 28 which is mounted onthe outer end of a shaft 29. The shaft 29 supports a gear 30 whichmeshes The gear 3I is mounted on a rotatable shaft (not shown) whichalso supports a gear 32. The gear 32 meshes with a rack bar 33 which isiixedly mounted on the underside of the table I I. foregoing disclosurethat a rotary motion of the manually operable traverse wheel 28 isimparted to cause a longitudinal traversing movement of A reversing andcontrol valve unit is provided L which is connected with pipes 4I andl2v with the brackets 3l and 39 respectively toconvey fluid.`

It will be readily apparent from theV or driving plate 45. h l y n Inorder to attain the main object of the invenunder pressure to and fromopposite ends of the cylinder 35. The table actuated reversing lever A21 serves to actuate the reversing valve. A start and stop lever 43 isprovided to actuate a startstop and speed control valve contained in thevalve unit 48. This hydraulic table reciprocating mechansiniis identicalwith that disclosed in the prior U. S.Patent to Wood No. 2,071,677 towhich `reference may be had for details of disclosure not containedherein.

The headstock I2 is provided lWith-the usual Work supporting center 46and a rotatable face bushing 48 which mates With the headstock .cen-

ter 46. n

The face or driving plate 45 supports a pair of diametrically opposeddrivingstuds or bolts 49 and`59.- The bolts 49`and 59 are provided Withintegral'heads 5l and- 52` respectivelywhich are supported in aVdiametrically opposed radiallyextending'T-shaped slots 53 and 54respectively Y formed in the faceplate 45." Locking nuts 55 and 56 areprovided 'to lock the bolts 49 and 56 respectivelyV in adjustedpositions relative to the platev 45.f A The driving bolts 49 and 58 passthrough-clearance holes 51 and 58 respectively formed ina flange I59which is an integral part of the chuck 4'1. A pair of compressionsprings 60 and 6I surround the'bolts 49 and 59 respectively'Y and areinterposed between the flange 59 and nuts 52 and`63. The springsv andlserve yieldably to support and maintain the chuck 41 with thecenterbushing 48 in engagement with the headstock center 46.

`The main body portion of the chuck 41 is formed with atrue cylindricalperipheral surface, the right hand end of which is support'for` rotationby means of a steadyrest 65.l The steadyrest-65 is adjustably clampedonthe Work table'lll and is providedV With'a pair ofadjustablymountedrsteadyrest shoes 66 and 61 which engage and supportthe periphery of the chuck 41. The lshoes 56 and 51 may be adjusted bymeans of then usual kadjusting screws-68 and 69 respectively. A bracket18 is either formed integralwith or fixedly mounted onthe steadyrest65.. The bracket 18 servesfas a support fora shoeY 1I which engages theupper portion of the chuck 41, thus forming a three point support forthe right `hand end of the chuck 41. An adjusting `screw 12 is providedto facilitate adjustment of the shoe'1l'relativeto the bracketl. Thechuck 41 is provided With'a longitudinally extending cylindricalaperture 15, the axis 'of Whichis parallel to the axis of rotation ofthe chuck.' VvThe axis of the aperture 15 is spaced from the axis ofrotation ofthe chuck 41 by a distance equal. to the throw of thecrankpin to belground. A split bushing 1611s mounted in the right handend of the aperturel Y15. The bushing 16 is provided With a central'aperture 11 Which The chuck 41 is arranged to support a.

Vthe bushings 8| and 82 towards each other to clamping screw 80 whichpasses through a vclearance hole in a bushing 8l and is screw threadedinto a bushing 82. The bushings 8l and 82 are supported in atransverselyextending hole 83 formed in the chuck 41 (Fig. 3). The bushings 8l and82 are-provided Withsurfaces 84 and 85 which engage and mate with thevouter peripheral surface of the split bushing 16. It will be readilyapparent from the foregoing disclosure that tightening the clampingscrew 88 will draw clamp the split bushing 16 and the crankshaft 18 tobeground in -the chuck 41. Before clamping the crankshaft 18 is rotarilyadjusted so that the axis of acrankpin 19 to be ground is aligned Withthe axis of rotation of the chuck 41.

- In 'order to steady the crankshaft 18 during a grinding operation, aslidably mounted center 85 is provided Which engages a center hole 84formed in the end of the crankshaftg'l. The

center 85 is formed integral with a lslidablyv mounted member 86A whichslides Within the aperture 15. Av compression spring 81 which isinterposed between the member 86 and an end cap 89 serves yieldably tomaintain the center 85 in engagement With the center hole 84. -v

The operation of the improved crankpin grinding attachment will bereadily apparent from the foregoing disclosure. The crankshaftsupporting chuck 41 is mounted as illustrated in'Fig. 2 with the centerbushing yieldably Vvmaintained in engagement with the-center 45. Theother endv ofthe-`chuck is supported and steadied by the shoes 66, 61and'1l of the steadyrest 65. The chuck 41 is driven by the face plate45'by means ofthe driving studs or bolts 49 and 50. rvA crankshaft 18 tobe ground is inserted Within' the split bushing 16 and moved axiallyuntil the center hole 84 engages the center 85 and Vmoves the supportingmember 86 tow-ard the left (Fig. 2) to compress the spring 81. Thecrankshaft 18is then rotated Within the split bushing 16 until the crankarm90 (Fig. 2) engages a locating stop 9| (Fig. 3) to position thecrankpin 19 to be ground in axial alignment with the axis of rotation ofthe chuck 41. lThe clamping screw 88 is then tightened to clamp thecrankshaft `18 in the chuck 41k for a grinding operation.

The work table l l may then be traversed longitudinally to position thecrankpin 19 opposite thergrinding wheel I5. The chuck 41 may then berotated and the grinding Wheel lil-fed toward the crankpin 19 to grindit to thedesired and predetermined size. v

It will thus be* seen that there has been provided by this inventionapparatus in which the I various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully f achieved.As Inany possible em bodiments may be made yof the above inventionlongitudinally movable Work table, a headstock on said table having arotatable face plate and a center, and a crankshaft supporting chuck,

yieldable means drivingly to hold one end of said `crankshaft with itsaxis offset from the axis of rotation by a distance equal to the throwof the crankpin to be ground.

2. In a cylindrical grinding machine having a longitudinally movableWork table, a headstock on said table having a rotatable face plate anda center, and a crankshaft supporting chuck, yieldable means drivinglyto hold one end of said chuck on said center, a steadyrest on said tablerotatably to support the other end of said chuck, and an offsetcrankshaft supporting and clamping means on said chuck to support acrankshaft so that the axis of the crankpin to be ground is in alignmentWith the axis of rotation of the chuck.

3. In a cylindrical grinding machine having a longitudinally movabletable, a headstock on said table having a rotatable face plate and acenter, and a crankshaft supporting chuck, yieldable means drivingly tohold one end of said chuck on said center, and a steadyrest on saidtable rotatably to support the other end of said chuck, said chuckhaving a split bushing to support a crankshaft with the crankpin to beground in axial alignment with the axis lof rotation of said chuck and abinder screw on said chuck to clamp said bushing and crankshaft in saidchuck for a grinding operation.

4. In a cylindrical grinding machine having a transversely movablerotatable grinding wheel, a longitudinally movable work table, aheadstock having a rotatable face plate and a center which is supportedon said table, and a crankshaft supporting attachment including a frame,a center hole in one end of said frame adapted to mate with theheadstock center, yieldable means drivingly to hold said frame on saidcenter, a steadyrest to support the other end of said frame, and acrankshaft supporting chuck formed in said frame.

5. In a cylindrical grinding machine having a transversely movablerotatable grinding wheel, a longitudinally movable work table, aheadstock having a rotatable face plate and a center which is supportedon said table, and a crankshaft supporting attachment including acylindrically shaped frame, a center hole in one end of said frameadapted to mate with the headstock center, yieldable means drivingly tohold said frame on g said center, a steadyrest having adjustable shoesto support the other end of said frame and a crankshaft supporting chuckformed in said cylindrical frame, the axis of said chuck being offsetfrom the axis of rotation of said frame by a distance equal to the throwof the crankpin to be ground.

6. In a grinding machine having a transversely movable rotatablegrinding Wheel, a longitudinally movable work table, a headstock havinga rotatable face plate and center on said table, a crankshaft supportingattachment including a cylindrically shaped frame, yieldable meansdrivingly to support one end of said attachment lframe on said center, asteadyrest on said table having adjustable shoes to support the otherend of said frame, an aperture in said frame parallel to the axis of theframe and spaced from said axis by a distance equal to the throw of thecrank-pin to be ground, a spring pressed center in one end of saidaperture to engage and support one end of a crankshaft to be ground, anda crankshaft supporting chuck in said aperture adjacent to the end ofsaid frame to support a l. crankshaft with the axis of the crankpin tobe ground aligned with the axis of rotation of the frame.

ALBERT G. BELDEN. CARL G. FLYGARE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 945,979 Norton et al. Jan. 11,1910 1,079,494 Jantsch Nov. 25, 1913

